It looks like you might have an identifier, or maybe a portion of your script that has a Null value or Zero where a number is required, like a divisor, or something. It looks like you are summing something, and then dividing it by another sum. Maybe there is an empty field or a missing value that QV does not like. I would rebuild your script formulas in a chart object, like a straight table. put each needed field in it's own column and see if there are any zeros or Nulls where a number is expected.
That is where I would start.